class_docstr: test mixin with layout properties
code: def test_align_items_extra_options(self):
      template = self.DummyTemplate(align_items="top")
      assert template.align_items == "top"
      assert template.layout.align_items == "flex-start"
  
      template.align_items = "bottom"
      assert template.align_items == "bottom"
      assert template.layout.align_items == "flex-end"
  
imports: from unittest import TestCase
  import pytest
  import traitlets
  import ipywidgets
  from ipywidgets.widgets.widget_templates import LayoutProperties
label_desc: Use image node_id 2 for calling the TestLayoutProperties obj's underlying member method code with example usage: obj.test_align_items_extra_options() without return types